Device for producing roll-shaped packets of bags of plastic

ABSTRACT

A device for producing roll shaped packets of bags of plastic foil, whereby continuously a web is supplied in which the bags are held together through perforations, said device comprising two winding heads having lengthwise retractable and extendible winding fingers which can also be spreaded, the web during winding of one head running in between the fingers of the other head. Both winding heads are mounted at diametrically opposed locations of a revolvable disc having two fixed positions. The supply means comprise one roller within the line of circulations of the winding head situated at one side with respect to the vertical through the axis of the revolvable disc, and one roller outside the said line of circulation and situated at the opposite side of said vertical. A switch mechanism under control of a bag unit counter sets the non-operative head into rotation and brings the operative head to a standstill, whereby a perforation is caused to break and the winding is taken over by the head just started.

0 United States Patent 1191 1111 3,881,665

Leloux May 6, 1975 DEVICE FOR PRODUCING ROLL-SHAPED [57] ABSTRACTPACKETS 0F BAGS OF PLASTIC A device for producing roll shaped packets ofbags of [75] Inventor: Arnoldus Willem Jan Leloux, plastic foil, wherebycontinuously a web is supplied in Dedemsvaart, Netherlands which thebags are held together through perforations, said device comprising twowinding heads having [73] Asslgnee' Wavm Zwone Netherlands lengthwiseretractable and extendible winding fingers [22] Filed: Dec. 28, 1973which can also be spreaded, the web during winding of Appl. No.: 429,116

[52] US. Cl. 242/67.3 R; 242/56 A [51] Int. Cl B65h 17/02 [58] Field ofSearch 242/67.l R, 67.2, 67.3 R, 242/64, 56 A [56] References CitedUNITED STATES PATENTS 2,935,273 5/1960 Hoeffgen 242/78.l X

3,704,835 12/1972 Harley 242/56 A 3,783,750 l/l974 Josephus... 242/56 A3,784,122 1/l974 Kataoka 242/56 A 3,814,342 6/1974 Fujiwara 242/56 APrimary Examiner-Edard J McCarthy Attorney, Agent, or Firm-Edmund M.Jaskiewicz one head running in between the fingers of the other head.

Both winding heads are mounted at diametrically opposed locations of arevolvable disc having two fixed positions.

The supply means comprise one roller within the line of circulations ofthe winding head situated at one side with respect to the verticalthrough the axis of the revolvable disc, and one roller outside the saidline of circulation and situated at the opposite side of said vertical.

A switch mechanism under control of a bag unit counter sets thenon-operative head into rotation and brings the operative head to astandstill, whereby a perforation is caused to break and the winding istaken over by the head just started.

11 Claims, 12 Drawing Figures PATENTEDNAY 61975 SHEET 01 [IF 1 1PATENTEDIZ-KY ems I 3,881,665

SHEET 020$ 11 PATENTEDMAY ems 3,881,665

SHEET U3DF 11 miij PATENTEDMAY 61975 3,881,665

SHEET OR 0F 11 PAYENTEDHAY 61975 SHEET USUF 11 PATENTED MAY e 1975 SHEET07 0F 11 m Q 3 5 mm S a m Ma -Hm- WJENTEDHAY 6 I975 SHEET DBUF 11 RmFmNm2 PATENTEUMAY 6i975 SHEET 09 0F 11 PA'I'ENTEDMAY 51975 SHEET H3,881,665

DEVICE FOR PRODUCING ROLL-SHAPED PACKETS OF BAGS OF PLASTIC Thisinvention relates to improvements in a device for producing roll-shapedpackets of bags of plastic foil, more specifically those wherebycontinuously a web is supplied in which the bags are held togetherthrough perforations.

A typical device of the type here involved is that which is disclosed inBritish Pat. Specification No. 1,332,544, this device comprising:

two winding heads, each having a plurality of winding fingers which arelengthwise retractable and extendible between an operative position anda retracted position, and which can be moved towards each other betweena spreaded position and an inner position for winding and fordisengaging, respectively,

the web supply guiding and the Winding heads being arranged one withrespect to the other such that during windings of one head the web runsin between the winding fingers of the other head,

and the spacing between the heads being chosen such that there is at anymoment at least one web perforation between them,

further under control of a counter for the number of bag units supplied,a switch mechanism which sets the non-operative head into rotation andbrings the op erative head to a standstill,

under the tensile stress thus produced in the web between the heads aperforation being caused to break and the winding being taken over bythe head just started.

after which the head brought to a standstill is drawn with its fingersout of the roll wound and subsequently, after a relative change of theweb direction and the heads, the fingers of this head are extended againwith the web running in between these fingers.

This prior device requires a rather large space. The device is intendedto work up without interruption web material of such length that one mayspeak of a continuous process. In connection therewith it is desirableto have at least two winding heads, so that while a formed roll orpacket is disengaged from one head the winding on the other head may goon. For transferring the supplied web from one head to the other theprior device makes use of a relatively big swinging arm which isprovided at its extreme end with a second lever arm having a pair ofreversing rolls. In connection with the big swing of this reversinglever a rather great deceleration in the take up speed of the foil webis created and such deceleration must necessarily be compensated forwith an appropriate mechanism as is known in the art. Also the windingheads are mounted at fixed locations, so that the rolls produced have tobe taken off at two locations in the machine. Finally in the priordevice the winding is done at a relatively great diameter, having forconsequence that the packet after disengaging it from the winding headhas as a whole, a poor degree of stiffness. This appears particularlywhen the user has torn off several bags for his use; the remainingportion of the packet then often gets loose so that one can hardly speakanymore of a packet 01' roll that can be easily handled. In this respectit would be very advantageous to produce a roll wound on a smalldiameter, which would remain, when successively tearing off the bags foruse, roll-shaped and of maximum stiffness up to the end.

Therefore the present invention aims to provide a device for the purposementioned which meets the aforementioned disadvantages and in whichother advantages can be gained. More specifically the invention has forits object a compact, reliable, fast operating device for producingrollshaped packets of bags having a high degree of stiffness.

In accordance with the present invention both winding heads are mountedat diametrically opposed locations of a revolvable disc having two fixedpositions with respect to a fixed direction of supply of the foil web,the supply means comprising one roller within the line of circulation ofthe winding head situated at one side with respect to the verticalthrough the axis of the revolvable disc, and one roller outside the lineof circulation of the winding heads situated at the opposite side ofsaid vertical.

In this way it has become possible when one of the winding stationscontains a sufficient length to simply put the other winding stationinto rotation, by which the web is caused to break of itself and thewinding on the following head is initiated immediately. During suchwinding there will be a sufficient opportunity for the stations tochange places by rotation of the disc, so that by the end of thisdisplacement the first station, having delivered the packet wound, isprepared again to take over.

Preferably, according to the invention, each of the winding headscomprises no more than two winding fingers at short spacing. Apart fromthe fact that these two fingers have for result a very small effectivewinding diameter of the roll the advantage is obtained that when windingis taken over onto the new head, and with a substantially constantwinding speed, the head will have obtained after one single revolutionalready a grip on the web sufficient to bring about breakage. Thus, atthe beginning of the winding on a new station, it is not necessaryanymore to initially apply a revolving veloc ity which is increased ascompared with the normal winding velocity in order to obtain the desiredgood grip on the web.

In the accompanying drawings:

FIG. 1 schematically illustrates the principle of operation of thedevice according to this invention, thought of as an elevation of therevolvable disc of the device.

FIG. 2 shows an elevation partly in section of the complete device.

FIG. 3 is a side elevation according to the arrows III in FIG. 2.

FIG. 4 8 incl. illustrate details of the drive, viz. as elevations andin part sections respectively, as viewed in the direction of the arrowsIV VIII incl. of FIG. 3.

FIG. 9a is, in its left hand portion, a horizontal section through theaxis of the revolving system of FIGS. 1 and 2, and in its right handportion a plan view, the latter portion being shown in section and on anenlarged scale in FIG. 9b, the machine being shown in both FIG. 9a and9b in a condition in which it has continued in its normal direction ofmovement further than the condition shown in FIGS. 1 and 2.

FIG. 10 is an elevation according to the arrows X-X in FIG. 9a, and

FIG. 11 is a section according to the arrows XI-XI in FIG. 9b.

First a concise description will be given of t manner in which thewinding takes place so that afterwards the function of the various partsin the further detailed description will become more clear. FIG. 1schematically represents the winding mechanism. A revolvable plate 1supports at diametrically opposed locations two winding stationsindicated as a whole by the reference numerals 2 and 2, respectively.The revolvable plate 1 is revolvable in the direction of the arrow P1and each of the winding stations is revolvable with respect to the plate1 in the direction P2 and P2, respectively. A guide roller for the foilis indicated at 4, said roller being rotatable with respect to themachine frame in the direction of the arrow P4. Said roller 4 issituated outside the area of the revolvable plate 1, i.e., at theleft-hand side of the connecting line through the winding stations 2, 2in the condition represented. A similar guide roller 5, also rotatablein the direction of the arrow P5 with respect to the machine frame,finds itself at the right hand side of the connecting line between thewinding stations 2, 2. Said roller 5 finds itself within the annulararea in wich the plate 1 rotates. Each of the winding stations comprisesa pair of wind ing fingers 6, 7 and 6', 7', respectively.

In the condition represented in FIG. 1 the winding takes place. The foilmaterial is supplied from the top and runs over the guide roller whichrotates at a circumferential velocity equal to the supply velocity ofthe foil, between the stationary winding fingers 6, 7 of the upperwinding station 2. In the standstill condition of this station the lineconnecting the winding fingers 6 and 7 is inclined under about 45 withrespect to the diameter going through the stations 2, 2. With thearrangement of the guide rollers 4 and 5 as represented the direction ofmovement of the foil 8 therefore extends under about right angles to theline interconnecting the winding fingers 6 and 7. Thereupon the foil isled around the guide roller 5 and subsequently runs further downwardlywhere the foil material is wound about the fast rotating winding fingers6, 7' of the station 2 into a roll 9.

When the roll 9 contains a sufficient Wound length the winding fingers6, 7 of station 2 are caused to ro tated at high speed. Thereby the foilmaterial which finds itself between station 2 and station 2 is drawntaut over the roller 5 causing breakage of the foil web is occur at thelocation of the perforation present. While in this way, during speedyrotation of station 2, the winding of the succeeding roll is initiated,station 2 continues to rotate at low speed in order to wind the lastpart of the foil. After several revolutions the fingers 6 and 7 areretracted and the produced roll 9 is taken off. Thereupon, the windingat station 2 being continued, the revolvable plate 1 is rotated slowlyuntil the operative station 2 will have reached the location of station2' at the bottom. Thereby the foil material is guided of itself againuntil it passes over roller 5 just like in the condition represented.When station 2' will have reached again the location of station 2, thefingers 6, 7' will be extended on either side of the foil web 8, whichmeanwhile proceeds, and therewith station 2 is ready to take over againin the manner described.

FIG. 2 shows an overall view of the whole winding device with the drivein form of a side elevation, partly in section. Top right in this figurethe revolvable plate 1 with the pair of winding stations 2, 2 is visibleas closure ofa housing, as a whole referenced by 10, containing thegreater part of the mechanism for retracting or extending, respectively,the winding fingers 6, 7 and 6', 7, respectively.

In the left hand portion of the drawing the various drives arerepresented comprising, opposite the revolvable plate 1 with the windingstations 2, 2', a similar revolvable plate 11 with a pair of drivingheads l2, 12'. The housing containing the drives is referenced as awhole by 13.

In the detailed description of the drive which is given below referenceis also made to FIG. 3, representing a section according to the arrowsIII-III in FIG. 2.

On the bottom of the housing two electric motors are visible. Motor 14is a high speed motor with the function of driving the winding heads.Motor 15 is a low speed motor having the function of intermettentlycausing a rotation over l of the revolvable disc which supports thewinding stations, and also of slowly driving each of the windingstations during the last revolutions after breakage of the foil web.

The high speed motor 14 has its shaft 16 provided with a pulley 17. Overthe latter an endless belt 18 extends. This belt 18 further extends overa pulley 19 which constitutes part of a coupling mechanism which will bedescribed in detail and which is referenced as a whole by 20(represented separately in FIG. 4). Further the belt 18 extends over apulley 21, which also constitutes part of a similar coupling mechanismreferenced as a whole by 22 (represented separately in FIG. 5).

As will be described in more detail it is in this way possible totransmit the high drive velocity through belt pulley 23 of couplingmechanism 20 upwardly by means of belt 24, and in similar manner withpulley 25 in the coupling mechanism 22 the high drive speed on belt 26can be transmitted upwardly. Belts 24 and 26 ultimately drive the driveheads of the winding stations.

The low speed motor 15 has its shaft 27 provided with two belt pulleys28, 29. Over pulley 28 a belt 30 extends which goes further over apulley 31 constituting again part of a coupling mechanism referenced asa whole by 32 (represented separately in FIG. 6). In this way as will beexplained in detail the low drive speed can, by means of pulley 33 incoupling mechanism 32 as well as through belt 34, be transmittedupwardly for slowly revolving the revolvable plate which supports thewinding stations.

The other pulley 29 of the low speed motor 15 drives a belt 35 extendingover pulley 36 of the coupling mechanism 20 as well as over pulley 37 ofthe coupling mechanism 22. In this way either of the coupling mechanisms20, 22 has supplied on a pulley the low drive speed being transmittableupwardly through pulley 23 with belt 24 and pulley 25 with belt 26,respectively, for driving the winding heads at low velocity during suchtime period as is necessary.

For belt 18 a tension roller 38 is provided, supported by a lever 40pivotable about a shaft 39. In similar manner belt 35 is tensioned bythe tension roller 41 supported by the lever 42 which is pivotable aboutthe shaft 43.

Now the various coupling mechanisms mentioned already will be described,with which the upwardly extending belts can be given desired speeds atdesired moments.

In FIG. 4 to the right of the coupling casing 44 pulley 36 is visiblewhich is driven from the low speed motor through belt 35. The couplingcasing 44 itself, which has an electric control, has not beenrepresented in detail because one may use for this any known structurecommercially available which is adapted for coupling two shafts havingcoinciding axes. To the left of the coupling casing 44 one finds firstpulley 19 driven from the high speed motor 14 through belt 18. Thenpulley 23 is driven, over which belt 24 extends which transmits thedrive speed upwardly. Either of pulleys l9 and 23 is fixedly attached tothe shaft end at the left hand side of the coupling casing 44. When thecoupling is disengaged it is thus possible to transmit the speed of thehigh speed motor through pulley 28 to pulley 23, irrespective of whetherpulley 36, which is driven by the low speed motor 15, is or is notactually driven. When coupling 4 is engaged the lower drive speed ofpulley 36 is transmitted to pulley 23, pulley 19 running along idle.

FIG. 5 shows the coupling mechanism 22 which for the greater partcorresponds with the one of FIG. 4. On the shaft end to the right of thecoupling casing 44 one finds pulley 37 which is driven from low speedmotor through belt 35. To the left of the coupling casing first pulley21 is provided, driven from high speed motor 14 through belt 18, andsubsequently pulley 25 through which belt 26 transmits the driveupwardly. Either of pulleys 21 and 25 is again fixedly attached to theshaft end. The operation is analogous to what was described withreference to FIG. 4. The only structural difference between FIG. 4 andFIG. 5 is that in FIG. 4 the hub 46 of pulley 23 projects to the rightwith respect to the pulley at the same side an intermediate piece 47being placed on the shaft, so that in the end pulley 23 has a certainspacing with respect to pulley 19. In FIG. 5 pulley 25 has been placedon the shaft in the reverse condition, i.e., with the extended portion46' of the hub to the left, beside it the intermediate piece 47' beingprovided, so that pulley 25 is lying more close to pulley 21. In thisway the mechanisms and 22 can be arranged symmetrically in the drivehousing, the belts extending one in front of the other.

FIG. 6 shows an axial section through the coupling mechanism 32. To theright of the coupling 48 proper a pulley 31 is placed on the shaft, saidpulley being driven from the low speed motor 15 through belt 30. To theleft of the coupling in this case only pulley 33 is provided, over whichbelt 34 transmits the driving motion upwardly. The coupling 48 proper inthis case is of a type which also contains a braking device for thedriven side, in this case the left hand side. Its function will beexplained later on.

The manner in which the drive speeds of the belts 24, 26 and 34 areworked up in the top of the housing 10 now appears from FIG. 7. Therevolving disc 11 is affixed to a shaft 51. This shaft is at 52rotatably bearing in the housing wall 13. On shaft 51 first, to the leftin FIG. 7, a belt pulley 53 is visible which is fixedly mounted onspindle 51 by means of a clamping socket 54. Belt 34 at any time bringsalong upwardly a low drive speed with which, through the fixedconnection between pulley 53 and shaft 51 and subsequently the fixedconnection between shaft 51 and disc 11, this disc can be given a slowrotation.

On shaft 51 further a bushing 55 is provided. At either end thereofpulleys 56 and 57 are fixedly attached by means of keyings 58 and 59respectively. For the rest pulleys 56 and 57 are, by means of a set ofbearing 60 and 61, respectively, rotatable with respect to shaft 51.Pulley 56 receives belt 24 coming from below and which, in the mannerdescribed, a high as well as a low drive speed can be given as desired,and it is this drive which is then transmitted immediately to pulley 57,independent of shaft 51. Over pulley 57 drive belt 62 extends (videFIGS. 2 and 3) to one of the heads.

On the aforementioned bush a pair of bearings 63 and 64, respectively,is provided for support of a pair of pulleys and 66 which areinterconnected for example by means of threaded bolts such as 67. Pulley65 receives belt 26 driven from below, which can be driven at high orlow speed as desired, so that this speed can be transmitted throughpulley 66 to belt 68 (vide again FIGS. 2 and 3) for driving the otherhead. Because of the arrangement with the bearings 63 and 64 thistransmission with the pulleys 65 and 66 is independent of bush 55 andpulleys 56 and 57 belonging thereto, as well as of shaft 51.

Each of the aforementioned belts 62 and 68 extends over an idle roller69 and 70, respectively. These rollers have identical structures. Roller70 is represented separately again in FIG. 8. In the latter figure it isvisible that disc 11 bears a short support 71, attached by means of abolt 72 threaded through an aperture 73 in the disc into a threaded bore74 of support 71. The other end 75 of support 71 supports a bearing 76for pulley 70. As a matter of course the structures of guide rollers 69and 70 are different in the length of their supports such as 71, suchthat this length is adapted to the spacing between pulleys 57 and 66,respectively, over which the concerned belts extend, and plate 11.

Thus belt 62 extends over guide pulley 69 and over pulley 77 where thehead 12 (FIG. 2) is driven. In symmetrical manner belt 68 extends overguide pulley 70 and drive pulley 78 for the other drive head 12' (videFIG. 2).

From the structure as described above it will be apparent that therunning of the pair of drive belts 62 and 68, so the rotation of thedrive heads 12 and 12, can take place independent of the drive which nowand then rotates the revolvable plate 1 1 as a whole; the two drivesdont hinder each other in whatever way.

The details of the upper drive head 12 are to be found in FIG. 9a. In abore 81 of disc 11 a cylindrical bush 82, having a flange 83 isprovided. Flange 83 is sunk at the back of disc 1 1. The bush withflange is affixed with respect to disc 11 by means of bolts such as 84.In the cylindrical aperture 85 of bush 82 a shaft 86 is providedrotatably supported by means of three bearings 87, 88, 89. At the rightend the shaft 86 supports a disc 90 on which a drive head 91 isfastened, for example by means of a pair of bolts such as 92. This head91 is, in a manner still to be described, adapted to impart rotation tothe winding fingers.

At the other side of the revolvable disc 11 an electromagnetic brake 92,93 is provided. This brake may be of any known, commercially availabletype, so that details need not be described. The part 92 of the brakeis, by means of a flange 94 and bolts such as 95, fixedly attached withrespect to the flange 83 of the cylindrical bush 82, so fixed withrespect to the disc I l. The rotating brake portion 93 is fixedlymounted onto the shaft 86. The shaft 86 also supports the alreadymentioned pulley 77, the whole being completed by the provision of avane 96 for the proximity switch which will be described later on. Thisvane 96 may also be of a known structure. Vane 96 may be fastened withbolts such as 97 against the outer face of pulley 77.

It is thus visible that the belt 62 extending over the pulley 77 may setthe drive head 91 for the winding fingers into rotation.

In FIG. 1 it was shown already that the winding fingers such as 6, 7 ineach of the winding stations should be brought to a standstill in afixed condition, viz. under about 45 with respect to the lineinterconnecting the two winding stations in the device. For only in thisway it is ensured that, while a station in the lowermost position suchas 2' in FIG. 1 is in operation, the fingers 6, 7 of the upper station 2can be extended on either side of the proceeding foil web 8, in orderthat the winding may be taken over. It is with a view to this functionthat the drive head represented in FIG. 9a is provided with a brake 92,93. With the aid of vane 96 and an associated proximity switch the brakeis energized at the desired moment, so that head 91 will come to astandstill in the desired condition. The proximity switch itself has notbeen represented in the drawing. The details of it, as well as of theelectrical circuitry with the control of the magnetic brake will notneed any further description for the man skilled in the art.

In FIG. 9a it is further visible that the extremities of the windingfingers 6, 7 directed towards the drive head 91 and which are madesubstantially cylindrical, are provided with bevelled faces 101. Thesebevelled faces are provided at the side of each finger directed towardsthe other finger, so directed towards the axis 102 of the drive head 91or the rotating winding station as a whole, respectively. The drive head91 is provided with a pair of cavities such as 103, the shape of whichcorresponds with the extremity of the drive finger, i.e., each of thesecavities is substantially cylindrical, such as at 104, but having aninclined face 105 at the side directed towards the axis 102 of thecavity 103. The functions of the bevelled face 101 and the abutting face105 for each of the fingers is that the fingers can be given twodifferent mutual spacings: the fingers are extended from right to leftin FIG. 9a with a small spacing, and when the bevelled face 101 abutsagainst the inclined face 105 each of the fingers will be forcedoutwardly over a small distance into the position represented in FIG.9a. For the right hand extremities of fingers 6 and 7 a similarprovision has been made which will be described later.

To the right in FIG. 9a and in FIG. 9b a partial representation is givenof the revolvable plate 1 with the details of the winding head 2cooperating with the drive head 12 described. The mechanism forretracting the extending again the winding fingers 6, 7 comprises ahousing 106, for the greater part circularly symmetric, having an axiswhich coincides with the already mentioned axis 102 of the drive head atthe left. This housing 106 is as a whole movable over a certain distancealong the aforementioned axis. For this purpose the housing has at therear a plate 107. This plate is provided with a bore in which a pipe orbush 108 is mounted, such that the axis thereof extends parallel to theaxis 102. This bush 108 preferably has a great length as compared withits diameter. On either end in the interior of the bush 108 a ballbearing such as 109 is provided, with the aid of which the bush ismovable in axial direction with respect to a guide pin 110, the end ofwhich may be fastened to plate 1 by means of a simple screw connection111 at the end.

In plate 107 a second bore 112 is provided for the end of a piston rod113 which constitutes part of a pneumatic cylinder 114 (vide also FIG.2). This pneumatic cylinder 114 can be lodged at short distance from theaxis 102 in the space between the revolvable plate 1 of the right handmachine portion 10 and the revolvable plate 11 of the left hand machineportion 13. By means of this cylinder/piston rod combination 114, l 13the housing 106 with the fingers 6', 7 is moved to the left and to theright at desired moments. In FIGS. 9a and 9b the housing 106 with thefingers 6' and 7 has been represented in the extreme left position, inwhich the winding fingers are extended into the space between therevolvable plates 1 and 11, so ready for winding, in FIG. 2 the housing106 being represented in the extreme right position in which the fingers6' and 7 have been retracted.

Again referring to FIG. 9b it is visible that inside the housing 106 abushing 115 is provided. This bushing 115 again has its axis coincidingwith the axis 102 and is rotatable about this axis inside the housing106. For this purpose the bushing 115 is supported inside the housing106 by means of three ball bearings 116, 117, l 18. In order to be ableto enclose the bearing 117 the housing 106 comprises a separate annularpart 1 19, the next bearing 118 being enclosed by means of the closingdisc 120. The entirety can be kept together for example by means ofbolts 121. The bearing 116 is enclosed by disc 122. The latter can besunk into the back of the revolvable disc 1. At the front of disc 1, atthe left side of FIG. 9b, a double ring 123, 124 is provided. In thisdouble ring by means of a bearing 125 a set of plates 126, 127 isrotatable. Making double rings 123, I24 and plates 126, 127 is done aswill be understood in order to be able to enclose the bearing 125. Thetwo rings 123 and 124 together are fastened to the revolvable disc 1 bymeans of bolts such as 128, bolts such as 129 fastening the two roatableplates 126, 127 one to the other. The front plate 127 is provided with apair of round apertures 130, 131 serving to let the fingers 6' and 7,respectively, pass through. The rear plate may have one single big roundaperture 132. The apertures 130, 131 have greater dimensions than thediameter of the cylindrical part of the winding fingers 6', 7' as far asis necessary in order to enable the lateral movement of these fingers(vide also FIG. 10).

The extreme ends of the two fingers 6', 7' lying to the right of thedouble plate 126, 127 are provided with a substantially square crosssectional area (vide FIG. 1 l These portions of the fingers arereferenced 136', 137. These square fingers heads are located in squareholes 138 and 139 respectively, in the bushing 115. In horizontaldirection in FIG. 11 (so in the direction at right angles to the planeof the drawing in FIG. 9b) the square finger heads 136, 137' are simplyslidable with a very small clearance inside the cross sectionaldimensions of the square hole 138 or 139, respectively. In the verticaldirection in FIG. 11 (so the vertical direction in the plane of drawingin FIG. 9b) the square holes 138, 139 are to a sufficient degree biggerthan the dimension of the square finger heads 136', 137 in the samedirection in order to allow for the desired displacement of fingers 6',7' in lateral direction one with respect to the other.

At the location where the cross sectional view of FIG. 1 l was takeneach of the square finger heads 136, 137 is provided at oppositelocations with a pair of block shaped members 140-143 incl. Thesemembers are fixedly attached to the square finger heads, but under acertain inclination of their axes with respect to the finger axis asrepresented. Each of these small blocks is guided in a correspondinginclined slot of rectangular cross sectional area 144-11147 incl.

At the location where each of the inclined slots reaches the inner wallof bushing 115 there is also provided a bore 148, at right angles to thebushing axis, in which a compression spring 149 is located which urges aplug 150 against the extreme edge of the small block concerned. 7

Near the rear end of the square heads 136, 137' an entirely similar setof small blocks is provided onto the finger heads, with correspondinginclined slots in the bushing 115, as indicated by 151.

Laterally through the two square finger heads 136', 137' a pin 152 isput through corresponding borings. This pin 152 has a clearance in thebore holes of the finger heads such that lateral displacement of thefinger heads with respect to each other is permitted, but it ensuresthat they do move together in axial direction.

In the absence of other forces the eight guide blocks will be urged,under the influence of the springs such as 149, obliquely away in thedirection of the axis 102, i

with the result that the fingers will take up a position in which theirmutual distance has the smallest value. When, by operation of thepressure cylinder 113, 114, the housing 106 with the fingers isdisplaced to the left at the extreme ends of the fingers 6, 7' withtheir bevelled faces such as 101 abut against the drive head such as 91at the opposite side, the fingers 6', 7 will experience a force directedto the right. The inclined blocks in the inclined slots of bushing 115then allow for a small relative displacement of fingers 6', 7' to theright, whereby simultaneously the fingers will move somewhat away fromeach other into the position represented in FIG. 9a and FIG. 9b. Whenthereupon a foil bundle is wrapped around fingers 6, 7', and the windingis ended, pressure is admitted again in the pressure cylinder 114 havingfor effect that the housing 106 starts to move to the right in FIG. 9aand 9b. Thereto the foil roll wound onto the fingers will ensure asufficient resistance in order that a minor relative displacement of thesmall blocks in the inclined slot in bushing 115 will take place, bywhich the fingers will move towards each other again. Thereby the rollof foil is disengaged. As the supply of pressure medium to the pneumaticcylinder 114 proceeds the housing 106 together with the winding fingers6, 7' will move to the right, the fingers will be fully retracted andthe produced roll of foil material will become free to be taken away.

At the rear of the housing 106 described above, just like at the rear ofthe drive head 12, 12, an electromagnetic brake 157, 158, is provided.The one brake portion 157 is attached to the end plate 120 of housing106, for example by bolts such as 153. The other brake portion 158 isarranged on a hub 154 which is, by means of a flange 155 and screws suchas 156, connected with the rear end of bush 115. This brake 157, 158 isenergized simultaneously with brake 92, 93 at the drive side.

The other winding head 2 is fully identical to the described windinghead 2'.

F IG. 2 shows that the right hand end of the guide rod 110, along whichthe housing 106 is movable under the influence of the pneumaticcylinder, is mounted in a revolvable disc 161. It will be understoodthat the other housing is mounted in similar manner. The disc again hasits axis coinciding with axis 102. The disc is rotatably mounted in theright hand machine wall 162, as indicated by 163, inside this mounting arotatable coupling 164 being provided for the supply of pneumatic mediumto the air cylinders such as 114.

What I claim is:

1. A device for producing roll-shaped packets of bags of plastic foilfrom a continuously supplied web in which the bags are held togetherthrough perforations, said device comprising:

two winding heads, each having a plurality of windin g fingers which arelengthwise retractable and extendible between an operative position anda retracted position, and which can be moved towards each other betweena spreaded position and an inner position for winding and fordisengaging, respectively,

the web supply guiding and the winding heads being arranged one withrespect to the other such that during winding of one head the web runsin between the winding fingers of the other head,

the spacing between said heads being such that there is at any moment atleast one web perforation between them,

a counter for indicating the number of bag units supplied and a switchmechanism responsive to said .counter to set the non-operative head intorotation and to bring the operative head to a standstill to increase thetension on said web between the heads whereby under the tensile stressthus produced a perforation is caused to break and the winding of theweb is taken over by the head just started into rotation.

said switch mechanism further retracting the fingers of the standstillhead out of the wound roll and subsequently, after a relative change ofthe web direction and the heads, extending again the fingers of thishead with the web running in between these fingers,

both said winding heads are mounted at diametrically opposed locationsof a revolvable disc to define two fixed positions with respect to afixed direction of supply of the foil web,

supply means for said web comprising a first roller within the line ofcirculation of the winding head situated at one side with respect to thevertical through the axis of the revolvable disc, and a second rolleroutside the line of circulation of the winding heads situated at theopposite side of said vertical.

2. A device as defined in claim 1, wherein each of the winding headscomprises no more than two winding fingers at short spacing.

3. A device as defined in claim 1, wherein opposite the winding heads apair of drive heads for the rotary movement of the winding heads isprovided, with which the fingers of each of the winding heads in theirextended conditions cooperate, said drive heads also being mounted on arevolvable disc which ensures the rotation of the disc supporting thewinding heads.

4. A device as decined in claim 3, wherein in each of the windingstations the displacement of the winding fingers from the condition inwhich the fingers lie close to each other to the spreaded condition andvice versa is obtained by providing each of the fingers with guidemembers arranged under an appropriate small angle relative to the fingeraxis, said members cooperating with guide faces arranged under acorresponding angle in a bushing which supports the fingers.

5. A device as defined in claim 2, wherein the fingers are arrangedinside a housing which is movable in the direction parallel to thefinger axis.

6. A device as defined in claim 5, wherein the displacement of thehousing occurs by pneumatic means.

7. A device as defined in claim 1, wherein the drive comprises at leastone high speed motor for the winding heads and a motor for therevolvable disc.

8. A device as defined in claim 7, wherein the motor for driving therevolvable disc is a motor running at relatively low speed, andtransmission means to said revolvable disc for additionally driving thedrive heads at the winding stations by said motor.

9. A device as defined in claim 8, wherein a belt drive is providedcomprising, in coaxial arrangement with the axis of the revolvable discwhich supports the drive heads, the following pulleys: one pulley whichis adapted to be driven from the high speed motor by intermediary of acoupling and having a fixed connection with a pulley by which therotation is directly transmitted to one of the drive heads, one pulleyindependent of the former but also adapted to be driven by the same highspeed motor and which has a fixed connection with a second pulley fordriving the second drive head, and finally a pulley adapted to be drivenfrom the other motor and having a fixed connection with the revolvabledisc which supports the drive heads.

10. A device as defined in claim 9, wherein the coupling mechanismconnecting the high speed motor with the two pulleys for the drive headsalso comprise pulleys adapted to be driven from the other motor.

11. A device as defined in claim 1, wherein each of the winding heads isprovided with means adapted to bring the rotary motion to a standstillwith a definite condition of the fingers.

1. A device for producing roll-shaped packets of bags of plastic foilfrom a continuously supplied web in which the bags are held togetherthrough perforations, said device comprising: two winding heads, eachhaving a plurality of winding fingers which are lengthwise retractableand extendible between an operative position and a retracted position,and which can be moved towards each other between a spreaded positionand an inner position for winding and for disengaging, respectively, theweb supply guiding and the winding heads being arranged one with respectto the other such that during winding of one head the web runs inbetween the winding fingers of the other head, the spacing between saidheads being such that there is at any moment at least one webperforation between them, a counter for indicating the number of bagunits supplied and a switch mechanism responsive to said counter to setthe nonoperative head into rotation and to bring the operative head to astandstill to increase the tension on said web between the heads wherebyunder the tensile stress thus produced a perforation is caused to breakand the winding of the web is taken over by the head just started intorotation. said switch mechanism further retracting the fingers of thestandstill head out of the wound roll and subsequently, after a relativechange of the web direction and the heads, extending again the fingersof this head with the web running in between these fingers, both saidwinding heads are mounted at diametrically opposed locations of arevolvable disc to define two fixed positions with respect to a fixeddirection of supply of the foil web, supply means for said webcomprising a first roller within the line of circulation of the windinghead situated at one side with respect to the vertical through the axisof the revolvable disc, and a second roller outside the line ofcirculation of the winding heads situated at the opposite side of saidvertical.
 2. A device as defined in claim 1, wherein each of the windingheads comprises no more than two winding fingers at short spacing.
 3. Adevice as defined in claim 1, wherein opposite the winding heads a pairof drive heads for the rotary movement of the winding heads is provided,with which the fingers of each of the winding heads in their extendedconditions cooperate, said drive heads also being mounted on arevolvable disc which ensures the rotation of the disc supporting thewinding heads.
 4. A device as decined in claim 3, wherein in each of thewinding stations the displacement of the winding fingers from thecondition in which the fingers lie close to each other to the spreadedcondition and vice versa is obtained by providing each of the fingerswith guide members arranged under an appropriate small angle relative tothe finger axis, said members cooperating with guide faces arrangedunder a corresponding angle in a bushing which supports the fingers. 5.A device as defined in claim 2, wherein the fingers are arranged insidea housing which is movable in the direction parallel to the finger axis.6. A device as defined in claim 5, wherein the displacement of thehousing occurs by pneumatic means.
 7. A device as defined in claim 1,wherein the drive comprises at least one high speed motor for thewinding heads and a motor for the revolvable disc.
 8. A device asdefined in claim 7, wherein the motor for driving the revolvable disc isa motor running at relatively low speed, and transmission means to saidrevolvable disc for additionally driving the drive heads at the windingstations by said motor.
 9. A device as defined in claim 8, wherein abelt drive is provided comprising, in coaxial arrangement with the axisof the revolvable disc which supports the drive heads, the followingpulleys: one pulley which is adapted to be driven from the high speedmotor by intermediary of a coupling and having a fixed connection with apulley by which the rotation is directly transmitted to one of the driveheads, one pulley independent of the former but also adapted to bedriven by the same high speed motor and which has a fixed connectionwith a second pulley for driving the second drive head, and finally apulley adapted to be driven from the other motor and having a fixedconnection with the revolvable disc which supports the drive heads. 10.A device as defined in claim 9, wherein the coupling mechanismconnecting the high speed motor with the two pulleys for the drive headsalso comprise pulleys adapted to be driven from the other motor.
 11. Adevice as defined in claim 1, wherein each of the winding heads isprovided with means adapted to bring the rotary motion to a standstillwith a definite condition of the fingers.